This invention relates to a pressure sensitive element to be used for detecting passengers seated on the seats of, for instance, an airplane or automobile, and more particularly to a sheet material used for the production of the pressure sensitive element and a method for producing the sheet material.
A pressure sensitive element made of an electrically insulating resilient substance such as rubber dispersed with electrically conductive particles has been widely known. The conduction mechanism of the element resides in that under application of pressure the electrically conductive particles dispersed in the resilient substance are brought into contact with each other so as to form electrically conductive paths therethrough. When the pressure is released, the conductive particles are brought back to the dispersed state exhibiting a high electric insulation. The resistance value of the pressure sensitive element varies over a wide range from 10.sup.7 ohm-cm or more to 10.sup.3 ohm-cm or less.
However, since the resistance of the pressure sensitive element depends on the proximity and contact of the particles under pressure, the resistance value tends to vary widely, thus entailing the drawback of poor reproducibility.